The present invention relates to exercise equipment and more particularly, to weight selection methods and apparatus.
Various weight selection methods and apparatus have been developed to provide adjustable resistance to exercise. In the case of exercise weight stacks, for example, several weight plates are arranged in a vertical stack and maintained in alignment by rods or other guide members. A desired amount of weight is engaged by selectively connecting a selector rod to the appropriate weight plate in the stack. The selector rod and/or the uppermost weight in the stack are/is connected to at least one force receiving member by means of a connector. The engaged weights are lifted up from the stack in response to movement of the force receiving member.
Some examples of patented weight stack improvements and/or features are disclosed in U.S. Pat. No. 3,912,261 to Lambert, Sr. (discloses an exercise machine which provides weight stack resistance to a single exercise motion); U.S. Pat. No. 5,263,915 to Habing (discloses an exercise machine which uses a single weight stack to provide resistance to several different exercise motions); U.S. Pat. No. 4,900,018 to Ish III, et al. (discloses an exercise machine which provides weight stack resistance to a variety of exercise motions); U.S. Pat. No. 4,878,663 to Luquette (discloses an exercise machine which has rigid linkage members interconnected between a weight stack and a force receiving member); U.S. Pat. No. 4,601,466 to Lais (discloses bushings which are attached to weight stack plates to facilitate movement along conventional guide rods); U.S. Pat. No. 5,374,229 to Sencil (discloses an alternative to conventional guide rods); U.S. Pat. No. 4,878,662 to Chern (discloses a selector rod arrangement for clamping the selected weights together into a collective mass); and U.S. Pat. No. 4,809,973 to Johns (discloses telescoping safety shields which allow insertion of a selector pin but otherwise enclose the weight stack).
Additional weight stack patents include U.S. Pat. No. 5,000,446 to Sarno (discloses discrete selector pin configurations intended for use on discrete machines); U.S. Pat. No. 4,546,971 to Raasoch (discloses levers operable to remotely select a desired number of weights in a stack); U.S. Pat. No. 5,037,089 to Spagnuolo et al. (discloses a controller operable to automatically adjust weight stack resistance); U.S. Pat. No. 4,411,424 to Barnett (discloses a dual-pronged pin which engages opposite sides of a selector rod); U.S. Pat. No. 1,053,109 to Reach (discloses a stack of weight plates, each having a slide which moves into and out of engagement with the weight plate or top plate above it); and U.S. Pat. No. 5,306,221 to Itaru (discloses a stack of weight plates, each having a lever which pivots into and out of engagement with a selector rod.
Still more weight stack improvements and/or features are disclosed in U.S. Pat. No. 772,906 to Reach (discloses weight plates which are interconnected by lever driven bolts); U.S. Pat. No. 848,272 to Thornley (discloses weight plates which are interconnected by rotating levers); U.S. Pat. No. 3,647,209 (discloses a selector rod which moves downward to a desired weight in a stack and then rotates into engagement with the desired weight); Soviet Union Pat. No. 1,258,447 (discloses a rotating cam which pushes spring-loaded plungers into engagement with respective weights in a stack); and Soviet Union Pat. No. 1,389,789 (discloses both a selector rod which moves downward to a desired weight in a stack and then rotates into engagement with the desired weight, and a rotating cam which pushes spring-loaded plungers into engagement with respective weights in a stack).
With respect to free weights, in general, weight plates are typically mounted on opposite sides of a bar. In relatively advanced systems, the bar is stored in proximity to the weight plates, and a selection mechanism is provided to connect a desired amount of weight to the bar. Some examples of patented barbell/dumbbell improvements and/or features are disclosed in U.S. Pat. No. 4,529,198 to Hettick, Jr. (discloses a barbell assembly having opposite side weights which are maintained in alignment on respective storage members and selectively connected to a handle by means of axially movable springs); U.S. Pat. No. 4,822,034 to Shields (discloses both barbell and dumbbell assemblies having opposite side weights which are maintained in alignment on a shelf and selectively connected to a handle by means of latches on the weights); U.S. Pat. No. 4,284,463 to Shields (discloses a dumbbell assembly having opposite side weights which are maintained in alignment on a base and selectively connected to a handle by means of cam driven pins on the weights); U.S. Pat. No. 5,637,064 to Olson et al. (discloses a dumbbell assembly having a plurality of interconnected opposite side weights which are stored in nested relationship to one another and selectively connected to a handle by means of a U-shaped pin); U.S. Pat. No. 5,769,762 to Towley, III et al. (discloses a dumbbell assembly having a plurality of interconnected opposite side weights which are stored in nested relationship to one another and selectively connected to a handle by various means); and U.S. Pat. No. 5,839,997 to Roth et al. (discloses a dumbbell assembly having opposite side weights which are maintained in alignment on a base and selectively connected to a handle by means of eccentric cams on a rotating selector rod.
Despite these advances and others in the field of weight selection, room for improvement and continued innovation remains.
An aspect of the present invention is to rotate a selector rod into engagement with one or more aligned weight plates to provide adjustable resistance to exercise movement. The selector rod has a dedicated weight support for each of the weight plates. On a first embodiment, the selector rod extends vertically and is movable axially into and out of a vertical stack of weights. On a second embodiment, the selector rod extends horizontally and is movable radially into and out of a horizontal stack of weights. Additional features and advantages of the present invention will become apparent to those skilled in the art from the more detailed description that follows.